It is generally recommended to use the oil grade specified by the motorcycle manufacturer for optimal performance and protection of the engine. In the case of the Yamaha FZ V2, the manufacturer's recommended oil grade is 20W40 or 20W50, depending on the climate and riding conditions.
While both the Motul 300V 10W40 and Motul 7100 20W50 oils you mentioned are suitable for motorcycles, it is important to consider the specifications recommended by Yamaha and the climate conditions in your area before making a switch. Here are a few points to consider:
Oil Viscosity: The first number in the oil viscosity rating (e.g., 10W or 20W) indicates its flow characteristics at low temperatures, while the second number (e.g., 40 or 50) represents the viscosity at higher temperatures. It's essential to choose an oil grade that matches the manufacturer's recommendations to ensure proper lubrication and protection under various operating conditions.
Climate and Riding Conditions: Consider the typical temperature range in your area and the type of riding you do. If you frequently ride in hot climates or engage in aggressive riding, a higher viscosity oil like 20W50 may provide better protection under high-temperature and high-stress conditions. On the other hand, a lower viscosity oil like 10W40 may be suitable for cooler climates or milder riding conditions.
Oil Specifications: Apart from viscosity, it is crucial to ensure that the oil you choose meets the necessary specifications recommended by the motorcycle manufacturer. These specifications may include factors such as oil additives, friction modifiers, and compatibility with the engine's internal components. Refer to the motorcycle's owner's manual or consult with a trusted mechanic to ensure compatibility with the specific oil you intend to use.
Personal Preference: If you are considering changing the oil grade, it is advisable to consult with a knowledgeable mechanic or Yamaha dealer who has expertise in motorcycle maintenance. They can provide personalized advice based on your specific needs and the conditions you ride in.
Ultimately, while it is possible to switch to a different oil grade, it's essential to consider the manufacturer's recommendations, climate conditions, and seek professional advice to ensure the best performance and protection for your Yamaha FZ V2.